<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"> <div> Ahh, you cannot use this type of construct </div><div><br></div><div> if (x .eq. PETSC_NULL_XXX) then</div><div><br></div><div> anymore.</div><div><br></div><div> Nor can you ever assign x = PETSC_NULL_XXXX</div><div><br></div><div> Instead use </div><div><br></div><div> if (PetscObjectIsNull(x)) then</div><div><br></div><div> or </div><div><br><div> if (.not. PetscObjectIsNull(x)) then</div><div><br></div><div> Also all PETSc objects are now null when they are declared so just write</div><div><br></div><div> Mat Kmat</div><div> if (PetscObjectIsNull(Kmat)) then</div><div> call MatCreate(PETSC_COMM_WORLD,Kmat,ierr)</div><div><blockquote type="cite"><div dir="ltr"><div style="margin-left: 80px;"> etc...</div></div></blockquote></div><div><div dir="ltr"><div style="margin-left: 80px;"><br></div></div></div><div> Barry</div><div><br></div><div><br></div><div><br><blockquote type="cite"><div>On Mar 24, 2025, at 11:14 AM, Sanjay Govindjee <s_g@berkeley.edu> wrote:</div><br class="Apple-interchange-newline"><div><div dir="ltr"><div>Hi Barry,</div><div>The call sequence happens across several routines. I believe it is as follows:</div><div style="margin-left:40px"><br> call PetscInitialize(PETSC_NULL_CHARACTER, ierr)<br> call MPI_Comm_rank(PETSC_COMM_WORLD, rank, ierr)<br> call MPI_Comm_size(PETSC_COMM_WORLD, ntasks, ierr)</div><div style="margin-left:40px"> Kmat = PETSC_NULL_MAT</div><div style="margin-left:40px"><br></div><div style="margin-left:40px"> if(Kmat.eq.PETSC_NULL_MAT) then</div><div style="margin-left:40px"> call MatCreate(PETSC_COMM_WORLD,Kmat,ierr)</div><div style="margin-left:80px"> etc...</div><div style="margin-left:80px"><br></div><div>Kmat itself is declared in a module</div><div><br></div><div style="margin-left:40px"> module pfeapc <br># include <petsc/finclude/petscksp.h><br> use petscksp<br> implicit none<br> <br> Vec :: rhs, sol, xvec<br> Vec :: yvec, zvec<br> Vec :: Mdiag, Msqrt<br> Mat :: Kmat, Mmat, Pmat<br> KSP :: kspsol<br> end module pfeapc <br></div><div><br></div><div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">-</div></div></div></div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Mon, Mar 24, 2025 at 7:15 AM Barry Smith <<a href="mailto:bsmith@petsc.dev">bsmith@petsc.dev</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div><div><br></div> How do you declare and initialize the matrix in usolve.F before calling MatCreate()? You should not initialize it with any value before the call.<div><br></div><div> Barry</div><div><br id="m_5472959707679588228lineBreakAtBeginningOfMessage"><div><br><blockquote type="cite"><div>On Mar 23, 2025, at 11:10 PM, Sanjay Govindjee via petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>> wrote:</div><br><div>
<div>
Barry,<br>
<br>
I now have a compiled version of my code using the main branch.
When I run however I am getting an error in matcreate_( ) when I try
to solve (actually just set up the matrix). The console window
reports<br>
<blockquote>[0]PETSC ERROR: matcreate_() at
/Users/sg/petsc-3.22.4main/gnu/ftn/mat/utils/gcreatef.c:14 Cannot
create PETSC_NULL_XXX object<br>
[3]PETSC ERROR: matcreate_() at
/Users/sg/petsc-3.22.4main/gnu/ftn/mat/utils/gcreatef.c:14 Cannot
create PETSC_NULL_XXX object<br>
[2]PETSC ERROR: matcreate_() at
/Users/sg/petsc-3.22.4main/gnu/ftn/mat/utils/gcreatef.c:14 Cannot
create PETSC_NULL_XXX object<br>
[1]PETSC ERROR: matcreate_() at
/Users/sg/petsc-3.22.4main/gnu/ftn/mat/utils/gcreatef.c:14 Cannot
create PETSC_NULL_XXX object<br>
<br>
</blockquote>
The debugger windows all report (modulo the pid):<br>
<blockquote>(lldb) process attach --pid 90952<br>
Process 90952 stopped<br>
* thread #1, queue = 'com.apple.main-thread', stop reason = signal
SIGSTOP<br>
frame #0: 0x00007fff69d92746
libsystem_kernel.dylib`__semwait_signal + 10<br>
libsystem_kernel.dylib`__semwait_signal:<br>
-> 0x7fff69d92746 <+10>: jae
0x7fff69d92750 ; <+20><br>
0x7fff69d92748 <+12>: movq %rax, %rdi<br>
0x7fff69d9274b <+15>: jmp 0x7fff69d9121d ;
cerror<br>
0x7fff69d92750 <+20>: retq <br>
Target 0: (feap) stopped.<br>
frame <br>
</blockquote>
The debugger reports for the stack:<br>
<blockquote>(lldb) thread backtrace<br>
* thread #1, queue = 'com.apple.main-thread', stop reason = signal
SIGSTOP<br>
* frame #0: 0x00007fff69d92746
libsystem_kernel.dylib`__semwait_signal + 10<br>
frame #1: 0x00007fff69d15eea libsystem_c.dylib`nanosleep + 196<br>
frame #2: 0x00007fff69d15d52 libsystem_c.dylib`sleep + 41<br>
frame #3: 0x0000000111acb04c
libpetsc.3.022.dylib`PetscSleep(s=10) at psleep.c:48:5<br>
frame #4: 0x0000000111722961
libpetsc.3.022.dylib`PetscAttachDebugger at adebug.c:458:5<br>
frame #5: 0x00000001162ec7c8
libpetsc.3.022.dylib`PetscAttachDebuggerErrorHandler(comm=0x000000011788fde8,
line=14, fun="matcreate_",
file="/Users/sg/petsc-3.22.4main/gnu/ftn/mat/utils/gcreatef.c",
num=62, p=PETSC_ERROR_INITIAL, mess="Cannot create PETSC_NULL_XXX
object", ctx=0x0000000000000000) at adebug.c:522:9<br>
frame #6: 0x00000001162ecdb0
libpetsc.3.022.dylib`PetscError(comm=0x000000011788fde8, line=14,
func="matcreate_",
file="/Users/sg/petsc-3.22.4main/gnu/ftn/mat/utils/gcreatef.c",
n=62, p=PETSC_ERROR_INITIAL, mess="Cannot create PETSC_NULL_XXX
object") at err.c:409:15<br>
frame #7: 0x000000011233ecad
libpetsc.3.022.dylib`matcreate_(a=0x00000001165fdc74,
b=0x000000010fcde8c8, ierr=0x00007ffee0460308) at gcreatef.c:14:3<br>
frame #8: 0x000000010f7cf072 feap`usolve_ at usolve.F:138:72<br>
frame #9: 0x000000010f942de2 feap`presol_ at presol.f:181:72<br>
frame #10: 0x000000010f8cb8d8 feap`pmacr1_ at pmacr1.f:555:72<br>
frame #11: 0x000000010f8c60ad feap`pmacr_ at pmacr.f:614:72<br>
frame #12: 0x000000010f86ae4f feap`pcontr_ at pcontr.f:1375:72<br>
frame #13: 0x000000010fc1215e feap`main at feap87.f:173:72<br>
frame #14: 0x00007fff69c4ecc9 libdyld.dylib`start + 1<br>
frame #15: 0x00007fff69c4ecc9 libdyld.dylib`start + 1<br>
<br>
</blockquote>
Here is a peek at the frame stack:<br>
<blockquote>frame #3: 0x0000000105c7104c
libpetsc.3.022.dylib`PetscSleep(s=10) at psleep.c:48:5<br>
45 <br>
46 #if defined(PETSC_HAVE_SLEEP)<br>
47 else<br>
-> 48 sleep((int)s);<br>
49 #elif defined(PETSC_HAVE__SLEEP) &&
defined(PETSC_HAVE__SLEEP_MILISEC)<br>
50 else _sleep((int)(s * 1000));<br>
51 #elif defined(PETSC_HAVE__SLEEP)<br>
(lldb) up<br>
frame #4: 0x00000001058c8961
libpetsc.3.022.dylib`PetscAttachDebugger at adebug.c:458:5<br>
455 while (left > 0) left = PetscSleep(left) - 1;<br>
456 }<br>
457 #else<br>
-> 458 PetscCall(PetscSleep(sleeptime));<br>
459 #endif<br>
460 }<br>
461 #endif<br>
(lldb) up<br>
frame #5: 0x000000010a4927c8
libpetsc.3.022.dylib`PetscAttachDebuggerErrorHandler(comm=0x000000010c7f1de8,
line=14, fun="matcreate_",
file="/Users/sg/petsc-3.22.4main/gnu/ftn/mat/utils/gcreatef.c",
num=62, p=PETSC_ERROR_INITIAL, mess="Cannot create PETSC_NULL_XXX
object", ctx=0x0000000000000000) at adebug.c:522:9<br>
519 if (fun) (void)(*PetscErrorPrintf)("%s() at %s:%d
%s\n", fun, file, line, mess);<br>
520 else (void)(*PetscErrorPrintf)("%s:%d %s\n", file,
line, mess);<br>
521 <br>
-> 522 (void)PetscAttachDebugger();<br>
523 abort(); /* call abort because don't want to kill
other MPI ranks that may successfully attach to debugger */<br>
524 PetscFunctionReturn(PETSC_SUCCESS);<br>
525 }<br>
(lldb) up<br>
frame #6: 0x000000010a492db0
libpetsc.3.022.dylib`PetscError(comm=0x000000010c7f1de8, line=14,
func="matcreate_",
file="/Users/sg/petsc-3.22.4main/gnu/ftn/mat/utils/gcreatef.c",
n=62, p=PETSC_ERROR_INITIAL, mess="Cannot create PETSC_NULL_XXX
object") at err.c:409:15<br>
406 if (p == PETSC_ERROR_INITIAL && n !=
PETSC_ERR_MEMC) (void)PetscMallocValidate(__LINE__,
PETSC_FUNCTION_NAME, __FILE__);<br>
407 <br>
408 if (!eh) ierr = PetscTraceBackErrorHandler(comm,
line, func, file, n, p, lbuf, NULL);<br>
-> 409 else ierr = (*eh->handler)(comm, line, func,
file, n, p, lbuf, eh->ctx);<br>
410 PetscStackClearTop;<br>
411 <br>
412 /*<br>
(lldb) up<br>
frame #7: 0x00000001064e4cad
libpetsc.3.022.dylib`matcreate_(a=0x000000010a7a3c74,
b=0x0000000104e3e8c8, ierr=0x00007ffeeb300308) at gcreatef.c:14:3<br>
11 PETSC_EXTERN void matcreate_(MPI_Fint *a, Mat *b,
PetscErrorCode *ierr)<br>
12 {<br>
13 PetscBool null_b = !*(void**) b ? PETSC_TRUE :
PETSC_FALSE;<br>
-> 14 PETSC_FORTRAN_OBJECT_CREATE(b);<br>
15 CHKFORTRANNULLOBJECT(b);<br>
16 *ierr = MatCreate(MPI_Comm_f2c(*(a)), b);<br>
17 if (*ierr) return;<br>
(lldb) up<br>
frame #8: 0x000000010492f072 feap`usolve_ at usolve.F:138:72<br>
135 onnz => mr(np(246):np(246)+ilist(2,246)-1)<br>
136 dnnz => mr(np(247):np(247)+ilist(2,247)-1)<br>
137 <br>
-> 138 call MatCreate(PETSC_COMM_WORLD,Kmat,ierr)<br>
139 call
MatSetSizes(Kmat,numpeq,numpeq,PETSC_DETERMINE,<br>
140 & PETSC_DETERMINE,ierr)<br>
141 if(pfeap_bcin) call
MatSetBlockSize(Kmat,nsbk,ierr)<br>
</blockquote>
<blockquote><br>
</blockquote>
<pre cols="72">--
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Sanjay Govindjee, PhD, PE
Horace, Dorothy, and Katherine Johnson Professor in Engineering
Distinguished Professor of Civil and Environmental Engineering
779 Davis Hall
University of California
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</pre>
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